I think it’s fair to say that growth stock Heartflow (NASDAQ:HTFL) is flying under the radar right now. That’s understandable, as this medical technology firm only went public last summer and still has a small $2.5bn market cap.

However, Heartflow is experiencing rapid growth as it revolutionises heart disease diagnosis with its AI tools. And as we know, the market is going crazy for many fast-growing AI firms today. 

Might this become one of the next big AI winners?  

Personalised AI-powered diagnostics 

In the US today, there’s a heart attack every 40 seconds. And cardiovascular disease is the number one cause of death globally.

Heartflow’s proprietary technology could help this fall significantly over the next decade via earlier and more precise diagnosis. The US firm uses AI to create personalised 3D visualisations of a patient’s coronary arteries from CT scans. 

Put simply, its software shows doctors exactly how much a blockage is actually restricting blood flow without needing an invasive heart procedure. And its newer Plaque Analysis product, which enables detailed coronary anatomy of each patient, helps doctors predict the risk of a heart attack before it happens. 

The company’s software integrates seamlessly with existing hospital IT systems and an increasing number of heart scans have US insurance coverage.

How fast is it growing?

Last year, Heartflow’s revenue jumped 40% to $176m, with its installed base reaching 1,465 accounts in the US. Its US Plaque installed base grew to 489, which is encouraging. 

Even better, the company seems to have an almost untapped global growth opportunity. Because while international and other revenue grew 24% last year, it only made up $15.4m of the total (less than 9%). 

I would expect that to head higher, given the potential for adoption across Canada, Japan, and Europe.  

It’s worth noting that despite the company having high gross margins (76.8% last year), it’s still loss-making. Last year, the net loss was $116.8m, up from $96.4m the year before. 

Heartflow ended 2025 with $280m in cash, equivalents, and investments. But if it cannot reduce the losses, the company may need to raise more cash in future. 

For 2026, management has guided for revenue of about $230m, which would represent growth of roughly 26%. This puts the stock on a pricey forward-looking price-to-sales ratio of 11.

But looking at Wall Street forecasts, the firm isn’t expected to turn profitable until at least 2028. 

An AI winner in the making?

I do see a lot to like here. The company has 600+ patents worldwide and seems to have a long runway of growth, especially internationally.

However, determining whether Heartflow will become an AI winner is difficult. When Anthropic released a suite of agentic AI toolkits back in January, its share price crashed 44% in a month.

Something similar could happen again, even if the AI-powered software business isn’t disrupted. 

That said, when Baron Discovery Fund bought more Heartflow shares in Q1, it wrote: “It is hard to understand how Heartflow would be easily disintermediated, given the customer trust it has built up, and its FDA approved software based on significant clinical trials and millions of real-world CT scan analyses.” 

I do think this is an interesting high-risk, high-reward growth stock to look at. So I’ve popped it on my watchlist.